Summary: Luminara Unduli and Ahsoka Tano are transporting the captive Viceroy Nute Gunray to Coruscant to face trial. Count Dooku deploys his apprentice Asajj Ventress to make sure Gunray is either recaptured or killed rather than have him spill Separatist secrets.

——————————————————————————
Regarding how he got the part of Captain Argyus courtesy of http://jamesdb.com/

(12-08 Star Wars.com interview)

How did the character of Captain Argyus come your way?

When George Lucas was casting The Phantom Menace he, for one day maybe, considered me for the role of Anakin Skywalker and possibly found that I was too old. But it was an honor to meet his production crew during the audition and to be considered. I also grew up in the same town, Modesto, as George Lucas and lived about a mile away from him in Marin County when Star Wars came out. I would go to the end of the earth for George, as would anyone else.

How did you prepare for the role of Captain Argyus? What was the reason you wanted to use a different accent instead of your normal voice for the character?

I was using what I understand to be Standard Stage American, which is what they train you for in school for Shakespeare — think of it as an island between America and England. I wanted the character to be a bit arrogant so I used kind of a stuffy accent. I hope it worked, otherwise George won’t hire me again.